Biological Clock Day 2024 is on Sunday, April 28, 2024: What are biological clocks reset by?

Sunday, April 28, 2024 is Biological Clock Day 2024. 1200px-Biological_clock_human. ... Circadian rhythm

What are biological clocks reset by?

Biological clock may refer to:

Circadian rhythm, living organisms' adaptations to solar related rhythms

Age, as a general factor of female infertility

Early research into circadian rhythms suggested that most people preferred a day closer to 25 hours when isolated from external stimuli like daylight and timekeeping. However, this research was faulty because it failed to shield the participants from artificial light. Although subjects were shielded from time cues (like clocks) and daylight, the researchers were not aware of the phase-delaying effects of indoor electric lights. The subjects were allowed to turn on light when they were awake and to turn it off when they wanted to sleep. Electric light in the evening delayed their circadian phase. These results became well-known.

More recent research has shown that: adults have a built-in day, which averages about 24 hours; indoor lighting does affect circadian rhythms; and most people attain their best-quality sleep during their chronotype-determined sleep periods. A study by Czeisler et al. at Harvard found the range for normal, healthy adults of all ages to be quite narrow: 24 hours and 11 minutes ± 16 minutes. The "clock" resets itself daily to the 24-hour cycle of the Earth's rotation.

The classic phase markers for measuring the timing of a mammal's circadian rhythm are:

melatonin secretion by the pineal gland

core body temperature

plasma level of cortisol.

For temperature studies, subjects must remain awake but calm and semi-reclined in near darkness while their rectal temperatures are taken continuously. The average human adult's temperature reaches its minimum at about 05:00 (5 a.m.), about two hours before habitual wake time[citation needed], though variation is great among normal chronotypes.

Melatonin is absent from the system or undetectably low during daytime. Its onset in dim light, dim-light melatonin onset (DLMO), at about 21:00 (9 p.m.) can be measured in the blood or the saliva. Its major metabolite can also be measured in morning urine. Both DLMO and the midpoint (in time) of the presence of the hormone in the blood or saliva have been used as circadian markers. However, newer research indicates that the melatonin offset may be the more reliable marker. Benloucif et al. in Chicago in 2005 found that melatonin phase markers were more stable and more highly correlated with the timing of sleep than the core temperature minimum. They found that both sleep offset and melatonin offset were more strongly correlated with the various phase markers than sleep onset. In addition, the declining phase of the melatonin levels was more reliable and stable than the termination of melatonin synthesis.

One method used for measuring melatonin offset is to analyse a sequence of urine samples throughout the morning for the presence of the melatonin metabolite 6-sulphatoxymelatonin (aMT6s). Laberge et al. in Quebec in 1997 used this method in a study that confirmed the frequently found delayed circadian phase in healthy adolescents.

A third marker of the human pacemaker is the timing of the maximum plasma cortisol level. Klerman et al. in 2002 compared cortisol and temperature data to eight different analysis methods of plasma melatonin data, and found that "methods using plasma melatonin data may be considered more reliable than methods using CBT or cortisol data as an indicator of circadian phase in humans."

"More-or-less independent circadian rhythms are found in many organs and cells in the body outside the suprachiasmatic nuclei (SCN), the "master clock".

These clocks, called peripheral oscillators, are found in the oesophagus, lungs, liver, pancreas, spleen, thymus, and the skin. Though oscillators in the skin respond to light, a systemic influence has not been proven so far. There is also some evidence that the olfactory bulb and prostate may experience oscillations when cultured, suggesting that these structures may also be weak oscillators.

Furthermore, liver cells, for example, appear to respond to feeding rather than to light. Cells from many parts of the body appear to have freerunning rhythms.

What is a biological clock?

What is a biological clock?

The biological clock is referring to a females fertility clock in life. Most womens fertile days are almost over aroung 35-40 years of age. They are most fertile in their late teens and twenties. Egg quality goe down as females get older. So, as they get older, they start to feel the pressure that if they do not have a baby soon, they will not be physically able to.

Depression and biological clock?

Depression and biological clock?

The answer is different for everyone. Are you well enough to be a competent, loving mother? I decided not to have children, because I was too dysfunctional - long, severe depressions, and I would have neglected a baby no matter how hard I tried. It turns out the psychiatric medications that I was taking were causing MANY of my worst problems, and may have caused me to be totally disabled, by permanently worsening my bipolar problems, so I don't recommend them.

Those who say that having a baby will cure all your problems are full of crap. In this day and age, I can't believe anyone would say that! It is not a baby's job to fix its mother! Outrageous. i would suggest NOT turning to those friends for any more advice.

I often wish that I got knocked up when I was 16, before I took those awful medications. But in my case, the state would have taken my children away due to neglect (at times). You have to rate your daily functioning, keeping in mind the loss of sleep will be adding to your stress. If you can't do it, then you can't. Nobody knows for sure. The amount of other family support you have is an issue, too.

Generic Practical Depression tips (PRINT THEM OUT):

The library has self-help books on depression.

Many meds cause or worsen depression, including birth control, blood pressure, pain, acne, antipsychotic, anxiety (benzos) or sleeping medications, alcohol, illicit drugs and MANY others.

Hypothyroidism mimics depression . Too little sleep, or sleep disorders like sleep apnea, or interrupted sleep (crying baby, barking dog) can cause depression.

If depression is worse in winter, use a light box (10,000 Lux (light intensity) at about 20” - about $300 online, you don't need full spectrum, Sunray is a good brand). I have extra windows, painted the walls peach & yellow & have a skylight. There's a link to a cheaper lightbox & more info at psycheducation.org. Also you can try 1000 to 2000 IU of Vitamin D in winter. It may work, or may be placebo treatment.

Try meditation like progressive muscle relaxation or guided imagery. See The Anxiety & Phobia Workbook by Edmund Bourne. Free 15 minute guided imagery at healthjourneys.com and many free meditations at youtube.

Go out with friends, & if you don't have any, join a club e.g. hobby club, bowling league & MAKE yourself go. “Isolating” makes depression worse!

Exercise 1/2 hour a day, & anytime you feel depressed or anxious. LOTS OF RESEARCH SUPPORTS THIS as the most effective depression treatment of all.

Insomnia?: Go to bed & get up the same time each day, even weekends. Don't use your bedroom to watch TV, read or use the computer. Don't do stuff that revs you up before bed, like exercising & using the computer. Light from computer screens & TV wakes you up. Blue light is the worst offender – dim the lights and use an old-fashioned incandescent bulb the last hour. Make the bedroom very dark, even cover up the clock. Mask disturbing sounds with a fan or try soundsleeping.com or youtube, etc. Avoid caffeine after noon.

Put colorful, happy things around the house. Do nice things for yourself. Make a list of things that make you happy, like: bread fresh from the oven, the crisp sound of a saltine cracker breaking, fresh sheets on the bed, touching frost on the windowpane, etc. Read that list when you are down. Use comforting scents. I like vanilla & cloves.

Work on time management if you are overwhelmed. Cut back on other responsibilities so you can spend more time with friends & family. Ask for help with chores.

Spend more time with your pet, if you have one.

DON'T listen to sad music! Listen to upbeat stuff- same with movies & novels.

DISTRACT yourself. Read a novel, watch a comedy, go out with friends, play cards or a video game, whatever keeps your mind busy.

Volunteer. Helping others makes you feel better about yourself & you make a difference, too. If you are religious, your religion may help keep you involved in the community.

Put a half-smile on your face. Changing your expression is proven to help change mood.

Try free computerized cognitive behavioral therapy at moodgym.anu.edu.au. Also, if you have an abuse history, it is likely to be a major cause of your depression.

Holidays also on this date Sunday, April 28, 2024...